Patients with rheumatoid arthritis are at up to three times the risk for developing deep venous thrombosis and pulmonary embolism, a Taiwanese study found.

Action Points

Note that this Taiwanese population-based cohort study demonstrated an association between rheumatoid arthritis and risk of DVT and PE.

Be aware that the database could not account for factors that might mediate this relationship such as medication usage.

Patients with rheumatoid arthritis (RA) are at elevated risk for the development of deep venous thrombosis (DVT) and pulmonary embolism (PE), a Taiwanese study found.

After adjustment for age, gender, and comorbidities, patients with RA had more than three times the likelihood of DVT (HR 3.36, 95% CI 2.779-4.03) compared with healthy controls, according to Chia-Hung Kao, MD, of China Medical University in Taiwan, and colleagues.

In addition, they had twice the risk of PE (HR 2.07, 95% CI 1.55-2.76), the researchers reported online in Annals of the Rheumatic Diseases.

"This adds to the list of the many cardiovascular comorbidities seen in our rheumatic disease patients, especially [those with] RA," commented Joan M. Von Feldt, MD, of the University of Pennsylvania in Philadelphia, who was not involved in the study.

The chronic inflammatory state associated with RA also has been linked with abnormal clotting and prothrombotic factors and endothelial dysfunction.

However, little is known about the risks of thromboembolism among RA patients.

Risks also were higher for patients younger than 50, with hazard ratios of 5.55 (95% CI 3.40-9.07) and 3.13 (95% CI 1.26-7.77) for DVT and PE, respectively.

Additional marked increases were seen for patients with comorbidities. For patients with RA and comorbidities the hazard ratios for DVT and PE were 6.24 (95% CI 4.66-8.36) and 4.45 (95% CI 2.80-7.07), respectively, compared with individuals with neither RA nor comorbidities.

"Therefore, providing adequate care for patients with RA and comorbidities is an important step in preventing further development of DVT and PE," the researchers observed.

Additional analyses stratifying patients by time since the diagnosis of RA showed higher rates during the first 4 years for both DVT (HR 4.23, 95% CI 3.28-5.46) and PE (HR 1.95, 95% CI 1.31-2.91, P<0.0001 for both).

However, after 4 years the incidence of DVT decreased while that of PE increased. "DVT patients might subsequently develop PE, which might explain this discrepancy," the researchers noted.

A strength of the study was its national, population-based design, but limitations included a lack of information in the database on potential confounders such as lifestyle, steroid treatment, and severity of RA, so future research should address those issues, they suggested.

"These findings highlight the importance of a multidisciplinary team adopting an integrated approach to the intervention of potential risk factors among patients with RA," they concluded.

The study was funded by the Taiwan Department of Health and International Research-Intensive Centers of Excellence in Taiwan.

The authors reported no financial conflicts.

Reviewed by F. Perry Wilson, MD, MSCE Instructor of Medicine, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner

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